Probability-Based Assessment of Existing Concrete Bridges—Stochastic Resistance Models and Applications

This paper presents newly established probabilistic models of ultimate shear and bending resistance of typical reinforced concrete (RC) and prestressed concrete (PC) bridge cross-sections. These new models were developed using advanced analysis methods and the most recent data regarding variability in mechanical properties of material and cross-section geometry. The models also take into account the uncertainty related to the inaccuracy of the analysis method used to evaluate member resistance. In the second part of the paper, some of the developed models are applied to the probability-based assessment of an existing PC highway bridge that fails the traditional load capacity assessment performed using a standard partial safety factor method. The presented calculations clearly show the benefits of using the probabilistic methods in the assessment of existing bridges and demonstrate how straightforward the reliability analysis can become when the presented models are used.